HENDERSON'S HANDBOOK OF PLANTS. 



265 



ALA 



Ala. One of the lateral petals of a papilio- 

 naceous flower. Also a membranous ex- 

 pansion of any kind, as that round the 

 seed of a Bignonia, from the summit or 

 side of a seed vessel, or on the angles of 

 a stem. Formerly, the axil, but not now 

 employed in that sense. The word is 

 generally used in the plural, alee. 



Alabastrus. A flower bud. 



Alangiacece. A natural order of plants in- 

 habiting tropical Asia. "With the excep- ! 

 tion of the genus Nyssa, a native of this 

 country, all are trees or shrubs with in- 

 conspicuous flowers, structurally similar j 

 to those of certain Myrtles. Their fruit 

 is succulent and eatable, but not agree- ' 

 able to the taste. The principal genera 

 are Alangium and Nyssa. Eight or nine 

 species are all that are known. 



Alate. Winged ; bordered by a membran- 

 ous or leafy expansion, as the seeds of 

 the Maple, etc. 



Alatus. Winged. See Alate. 



Albefactio.A. condition of plants induced 

 by absence of light, commonly called 

 blanching, in which little or no chlorophyl 

 is formed, the peculiar secretions are di- 

 minished, and the tissues are tender and 

 unnaturally drawn out ; and thus some 

 plants, such as Celery and Sea-Kale, 

 which in a state of health a: - e tough, 

 unwholesome, and unfit for food, be- 

 come palatable and wholesome. If 

 light be restored, the plant may gradually 

 recover its tone ; but if it is absent for 

 any great length of time death is sure to 

 ensue. Some succulent plants, and those 

 which have tubers, will sometimes sur- 

 vive the first season, but in general the 

 confinement of a few months at the time 

 of growth is fatal. Flowers, when bleach- 

 ed, as of the flat-leaved Cacti, some- 

 times recover their color when exposed 



ALG 



to light, but Lilacs which are blanched 

 for ornamental purposes remain white, 

 though their leaves acquire a yellowish- 

 green tinge. 



Albescent. Where any color assumes a pale 

 tinge, or has a hoary appearance. 



Albumen. The matter that is interposed 

 between the skin of a seed and the em- 

 bryo, or the vitellus, if there is one. It 

 is of a farinaceous, oily, or horny consist- 

 ency, and surrounds the embryo wholly 

 or in part, and affords nourishment to 

 the young plant during the earliest stages 

 of germination. It is the floury part in 

 Corn, WTieat, Eye, and like grains ; the 

 oily part in Poppy seeds, etc.; and the 

 fleshy part in the Cocoanut. 



Albuminous. Furnished with albumen 

 when perfectly ripe. A term exclusively 

 applied to seeds. 



Alburnitas. A tendency to remain like al- 

 burnum. A disease of trees, when white 

 rings of wood are interposed among heart- 

 wood. 



Alburnum. The white and softer part of 

 wood, between the inner bark and heart- 

 wood, commonly known as sap-wood ; 

 the young wood before it conies to a 

 proper consistence. 



Algce. A large and important tribe of 

 Cryptogamia, by far the greater part of 

 which live either in salt or fresh water, a 

 few only deriving their nourishment from 

 the moisture contained in the surround- 

 ing air. Though many of them are con- 

 fined to particular kinds of rocks, and 

 have something resembling a root, it is 

 not probable that they draw any impor- 

 tant part ,of their nourishment from the 

 ^substance on which they grow. The 

 higher Algce have a distinct stem, from 

 which arise variously shaped expansions, 

 which often assume the semblance of 



